You're right, of course, they do not look the same when you put them side by side. I see a guy with a Lotus Elise on the same highway fairly often. When I looked in my rear view mirror and saw the Tesla coming up on my right, it looked like the Elise - but I wasn't sure. Then it went past and all I saw was it's @ss. From that angle they do look quite similar:

In my experience, this is a fundamental truth: HW companies that write SW is a recipe for disaster. Every time they try to create more than simple firmware to manipulate the HW, bad things happen.

Eventually the auto industry is likely to outsource their code to somewhere more capable, and we'll probably end up with a consolidation of just a few competing third-party automotive management systems. With that will come safer, more secure systems and fewer amateurish oversights on the part of the auto industry.